OAT experience
Thought I'd start by saying I do not work for OAT, I am a former student of theirs and for all the time I was there the management line was that pprune was a waste of time. (I guess it was all that OAT bashing that did it.)
I am a former APP student and thought the course was excellent - I thought overall all the tuition was top quality and, on the rare occasion when I had a problem, this was always sorted out in an adult and professional way.
The modular students get the same ground school and flight instructors so there should be no difference - and as far as I could tell the reasons for choosing modular or integrated were almost always personal, rather than being a case of one route better than the other.
I think the key really is to choose a school and a method (modular or integrated) that maximises your own chances of getting first time passes. There's no point in being integrated if you have 10 resits when you might have done better being a modular student. But clearly I can't make full comments on other schools or on the modular route since I have no experience of either. I can say that the route I chose worked well for me and that I enjoyed it.
If you are thinking of training why not ring up or email the pilot recruitment people at airlines and ask what sort of low hours pilots they are looking for. That's what I did and I discovered that the airline I wanted most to work for has a policy not to take on low hours modular students (which is still in place), although they will take on modular pilots with full ATPLs. Now I am working there, I think it's a stupid policy but it's unlikely to change in the near future. Other airlines don't care one way or the other, which, I think, just goes to show that, whatever way you train, you won't please everyone.